The colonists halted near the lake, about half a mile from the mouth of Red Creek.  A question of life or death was now to be decided.

Cyrus Harding, accustomed to the consideration of important crises, and aware that he was addressing men capable of hearing the truth, whatever it might be, then said,—­

“Either the lake will arrest the progress of the lava, and a part of the island will be preserved from utter destruction, or the stream will overrun the forests of the Far West, and not a tree or plant will remain on the surface of the soil.  We shall have no prospect but that of starvation upon these barren rocks—­a death which will probably be anticipated by the explosion of the island.”

“In that case,” replied Pencroft, folding his arms and stamping his foot, “what’s the use of working any longer on the vessel?”

“Pencroft,” answered Cyrus Harding, “we must do our duty to the last!”

At this instant the river of lava, after having broken a passage through the noble trees it devoured in its course, reached the borders of the lake.  At this point there was an elevation of the soil which, had it been greater, might have sufficed to arrest the torrent.

“To work!” cried Cyrus Harding.

The engineer’s thought was at once understood. it might be possible to dam, as it were, the torrent, and thus compel it to pour itself into the lake.

The colonists hastened to the dockyard.  They returned with shovels, picks, axes, and by means of banking the earth with the aid of fallen trees they succeeded in a few hours in raising an embankment three feet high and some hundreds of paces in length.  It seemed to them, when they had finished, as if they had scarcely been working more than a few minutes.

It was not a moment too soon.  The liquefied substances soon after reached the bottom of the barrier.  The stream of lava swelled like a river about to overflow its banks, and threatened to demolish the sole obstacle which could prevent it from overrunning the whole Far West.  But the dam held firm, and after a moment of terrible suspense the torrent precipitated itself into Grant Lake from a height of twenty feet.

The colonists, without moving or uttering a word, breathlessly regarded this strife of the two elements.

What a spectacle was this conflict between water and fire!  What pen could describe the marvelous horror of this scene—­what pencil could depict it?  The water hissed as it evaporated by contact with the boiling lava.  The vapor whirled in the air to an immeasurable height, as if the valves of an immense boiler had been suddenly opened.  But, however considerable might be the volume of water contained in the lake, it must eventually be absorbed, because it was not replenished, while the stream of lava, fed from an inexhaustible source, rolled on without ceasing new waves of incandescent matter.